Black civil rights groups and activists are pressing the nation’s first African American president to nominate a black woman to the Supreme Court, calling it an overdue historic first at a time of growing ethnic diversity and an intense debate about racial justice issues.

The pressure has been building since Justice Antonin Scalia’s sudden death gave President Obama what is likely his final opportunity to shape the high court, according to civil rights activists and people familiar with the selection process. At a recent White House meeting, for example, a number of activists directly urged the president to nominate an African American woman, pointing out that they had supported him at the polls in overwhelming numbers, said people in attendance.

“The appointment of an African American woman to the Supreme Court is essential to his legacy,” said Barbara R. Arnwine, president of the Transformative Justice Coalition, who helped launch one of two online petitions calling on Obama to defy fierce Republican opposition to any nomination being made and name a woman of color to the court.

The lobbying push comes as the White House intensifies its deliberations over replacing Scalia, whose Feb. 13 death kicked off a ferocious ideological battle for control of the Supreme Court. At least six federal judges are under consideration, sources have said, including two African Americans: Ketanji Brown Jackson, a U.S. district court judge for the District of Columbia; and Paul J. Watford, an appeals court judge in California.

But it is unclear how much the civil rights community’s concerns will figure into Obama’s calculus as he wrestles with how to approach Senate Republicans, who have vowed to block any nominee without holding a hearing. People familiar with Obama’s deliberations say he is considering a range of factors, including diversity, but is primarily focused on whether the candidate can win confirmation. According to those people, the president thinks that any nominee would be better for progressive causes than Scalia, who was an outspoken conservative.

President Obama is considering who to nominate to replace Justice Antonin Scalia on the Supreme Court. Here are seven people he's most likely to choose. (Sarah Parnass/The Washington Post)

When Obama was urged to choose a black woman at the Feb. 18 meeting with young and veteran civil rights leaders, his response focused on the prospects for confirmation. “His response was that he would be looking for the most qualified person who can get confirmed,” said one attendee, who spoke on the condition of anonymity to describe a private meeting.

This attendee said it would be “heartbreaking” if Obama — whose previous Supreme Court appointees were justices Sonia Sotomayor, a Hispanic woman, and Elena Kagan, a white woman — had three shots at the high court, and “none of them were African American.’’

Brandi Hoffine, a White House spokeswoman, said the president “takes his constitutional responsibility to fill the vacancy on the Supreme Court seriously, and the administration has consulted with a wide range of stakeholders, including senators from both parties, legal experts, advocacy groups, state and local leaders and others.”

“We’ve been clear,” she added, “that the individual the president ultimately nominates will be eminently qualified, hold a deep respect for the role of the judiciary in our democracy, and have tangible real-world experience in interpreting the law.”

The debate reflects the delicate balance that Obama has been trying to strike on racial issues, especially as the nation has focused on police brutality against African Americans and other racial justice issues in recent years. While diversity is important to Obama, supporters say he must consider the possibility of triggering a backlash from Republicans if they feel his Supreme Court pick is primarily about diversity.

“The last thing you want is Republicans saying they’re not meeting with who the NAACP and Al Sharpton tells them to meet with,” said Al Sharpton, the civil rights leader, who said he has told the White House he would “love to see an African American woman nominee” but that Obama should “nominate the most qualified person who can get confirmed.”

At the same time, the White House understands the stark political reality that the nomination could motivate the Democratic base and affect the presidential election. Democratic front-runner Hillary Clinton has been winning overwhelming support from African Americans in the primaries, but their turnout has not been as high as it was when Obama was on the ballot.

Rep. Keith Ellison (D-Minn.), one of several Congressional Black Caucus members who said lawmakers are also giving Obama a strong push to pick a black woman, said such a nominee would put intense pressure on Republicans. “If you get a nominee for the Supreme Court who is going to reflect a constituency who has never been on the court before — an African American woman — I think that you’re going to have a whole lot of African American women, a whole lot of African Americans and a whole lot of women . . . you’re going to see a whole lot of people fold their arms and say, ‘Okay, so what’s wrong with this candidate?’ ” he said.

“It’s not bad enough that [Republicans] are just completely violating their role as clearly defined in the Constitution; now they’re going to block the first black woman nominee?” Ellison added. “I mean, come on.”

In addition to Watford and Brown Jackson, judges under consideration for the high court include Sri Srinivasan and Patricia A. Millett, both appeals court judges in the District of Columbia; Jane L. Kelly, an appeals court judge based in Iowa; and Merrick Garland, chief judge of the U.S. Court of Appeals in the District of Columbia. Sources have said the White House is focusing on jurists with scant dis­cern­ible ideology and limited judicial records to help surmount the Republican opposition.

If Obama were to focus on nominating an African American woman, he would be working from a shortlist, people familiar with the selection process said. Attorney General Loretta E. Lynch, for example, was initially viewed as a contender, and NAACP President Cornell William Brooks said Tuesday that his organization has told the White House that many of its members want her considered.

But The Washington Post reported Monday that Lynch was no longer a candidate, which she confirmed Tuesday in a statement issued by her spokeswoman. “As the conversation around the Supreme Court vacancy progressed, the Attorney General determined that the limitations inherent in the nomination process would curtail her effectiveness in her current role. Given the urgent issues before the Department of Justice, she asked not to be considered for the position,’’ said the spokeswoman, Melanie Newman, in a statement.

That leaves Brown Jackson as the only African American woman known to be on the short list. She has degrees from Harvard University and Harvard Law School and had a top position at the U.S. Sentencing Commission but has only been a judge since 2013.

And it is rare for someone to go from a U.S. District Court directly to the Supreme Court, bypassing the appellate courts on which many justices have served. The last justice to make the leap was Edward T. Sanford, who was appointed in 1923 after serving 15 years as a federal judge in Tennessee.

Civil rights leaders said Tuesday that they regard Brown Jackson as a highly credible candidate. “Her name leaps out of the current list. It’s a question of intellect and broad life experience,’’ said Steve Phillips, founder of the social justice group PowerPAC+ and author of the book “Brown is the New White.’’

Phillips — whose organization along with the progressive group Democracy for America launched an online petition calling for a woman of color to be nominated — pointed out that some famous justices never served on the lower courts, such as Earl Warren, who was chief justice in the 1950s and 1960s after serving as governor of California.

Rep. Emanuel Cleaver II (D-Mo.), a former chairman of the Congressional Black Caucus, said Tuesday that caucus members are increasingly discussing Danielle Holley-Walker, who has been dean of Howard University Law School since 2014. Other civil rights leaders said her name has been forwarded to the White House, but it’s unclear whether she is under serious consideration.

Holley-Walker, 41, would be unusually young for a Supreme Court nominee but holds a distinguished résumé: Harvard Law, a clerkship with a federal appeals judge, a stint as a corporate litigator and a scholarly record focusing on education and civil rights. “There are a lot of emails and texts flying across the country right now concerning her,” Cleaver said. “She would be fabulous.”

Another widely discussed possible candidate, California Attorney General Kamala Harris (D), has told associates she is not interested in the position, said sources familiar with the process.

But activists and civil rights leaders are not giving up, urging Obama to cast a wider net in the search. “With the issues that are going to come before the court in the next decade, you need to make sure all perspectives are there,” said Benjamin L. Crump, a prominent civil rights lawyer who is president of the National Bar Association, the nation’s largest group of lawyers of color. He cited issues the high court could take up in coming years, such as school funding, police brutality and equal pay for women and minorities.

“We think an African American woman would be uniquely qualified to give a perspective that the court doesn’t have right now,’’ said Crump, who represented the family of Trayvon Martin, the black teenager shot and killed in a widely publicized 2012 incident.

And Brooks, the NAACP president, cited the nation’s growing ethnic diversity.“It’s 2016,” he said. “It’s high time for the consideration of African American women on the court. . . . It’s likely to be the president’s last chance.”